Invasion of Astro-Monster Plot Synopsis:

During a mission to the newly found Planet X, astronauts Fuji and Glenn are shocked to discover intelligent life. The Xians claim they have been forced into hiding by King Ghidorah and request help from the monsters that previously defeated him-- Godzilla and Rodan. In return they promise a miracle cure for all disease on Earth. Although suspicious, Fuji and Glenn agree to make the proposition to Earth's leaders. After the exchange the Xians reveal their agenda for planetary conquest. While they use Godzilla, Rodan and King Ghidorah to lay waste to the planet, Glenn, Fuji and a young inventor, Tetsuo, scheme to break the monsters free of alien control.